The present invention relates to a method for continuously printing uncased folded books, and to apparatus serving this purpose. In accordance with the prior art folded books are made, for example, by printing on one or both sides of a web or sheet. The sheets are then cut, folded, and collected in folded condition, and are then stitched or stapled to form an uncased book.
The German Pat. No. 335,110 discloses a rotary printing machine in which several printing plates can be placed on each platen cylinder with the longitudinal direction parallel to the respective cylinder axis. The imprinted web is then longitudinally cut, the cut web portions superimposed, and supplied to a folding apparatus where, in accordance with a number of pages which corresponds to the size of the machine, the sheets are folded to form a book and transversely cut. In the German Pat. No. 485,000, a method for printing books is disclosed, which does not start out from the usual bookbinder sheet, but provides on each sheet the same number of pages. The sheets are then assembled, superimposed, and separated into individual folded books. It is a disadvantage that each sheet of each kind must be first deposited, then assembled, and then cut so that such an arrangement is not suitable for rotary printing machines.
The U. S. Pat. No. 2,463,769 discloses a method for printing of books in which the production is to be increased by putting together a number of longitudinal web portions obtained by longitudinally dividing printed webs so that at the same time, two books can be made. The paper web is first printed by printing plates on which the columns extend in longitudinal direction about the cylinder, whereupon the web is cut into web portions which are superimposed whereupon the web portions are cut into sheets. The sheets are then transversely folded to obtain folded sheets with a predetermined number of pages, whereupon the respective number of folded sheets is assembled, sewn at two opposite edges, so that after binding of the folded sheets and separation of the twice bound folded sheets, two finished books are obtained. This method requires a number of steps which cannot be carried out with rotary printing machines.
The West German Pat. No. 1,107,640 also discloses a method for continuously manufacturing books in which several web portions are superimposed. Particularly for making brochures, two webs are longitudinally cut, the cut web portions superimposed, stapled, and so forth, and then transversely cut and deposited. This method is suitable for rotary printing machines, permits, however, only the manufacture of books having a limited number of pages, as required for school writing books.
Similar methods for making uncased books are disclosed in the British Pat. No. 948,710 in which also two books are manufactured at the same time, and in which the last step of the method is the separation of the two books.
Safety devices are known which automatically stop the printing machine when the web breaks or a sheet is not transported. Such devices operate mechanically or electrically, and it is also known to provide devices in which the machine is automatically stopped if a sheet is omitted, and starts again when the next sheet is supplied. Such a device is disclosed in the German Pat. No. 529,326 in which the stopping and starting of the printing machine is obtained by electromagnets.
Another apparatus which permits an intermittent printing by sheet printing machines, is disclosed in the West German AS No. 1,062,256. This device has the purpose to make any sequence of printed or empty pages by accordingly controlling the starting and stopping of the machine. Such control means are required for the printing of forms so that after the printing of a predetermined number of pages with consecutive numbers, pages can follow which are empty and unnumbered. The publication Pat. No. 1,062,256 uses for the starting and stopping of the printing rollers a mechanical eccentric control device.
Rotary printing machines for color prints are provided with devices for starting and stopping the printing rollers, as disclosed in the DDR Pat. No. 44,672 in printing machines of this kind. After the printing operation of the cylinder of the first printing device, it is necessary that the cylinders of the second printing device become operative only after several revolutions depending on the number of sheets transported between the printing devices. The same procedure must take place when the printing is stopped, and the second printing device must be stopped later than the cylinders of the first printing device by a number of revolutions corresponding to the number of sheets so that all sheets have past the first printing device, and are also imprinted by the cylinders of the second and following printing devices.
The West German AS No. 1,239,322 discloses an apparatus for starting and stopping the blanket cylinders of an offset printing machine. The printing blanket cylinder and the counter blanket cylinder, and also the respective platen cylinders, can be moved between a printing position and an inoperative position. For this purpose the two cooperating blanket cylinders are mounted in eccentric bearings which are angularly displaced by a linkage in such a manner that at the beginning of a printing operation, first the printing blanket cylinder is placed in a position cooperating with the respective platen cylinder, whereupon the counter platen cylinder is in a position cooperating with the respective counter blanket cylinder, whereupon the two blanket printing cylinders are placed in a cooperating position. When the machine is stopped, the two blanket printing cylinders are separated from each other, whereupon each blanket printing cylinder is separated from its associated platen cylinder, and the counter platen cylinder is separated from the associated counter blanket cylinder.
All the devices known for rotary printing machines printing on sheets, cannot be used for rotary printing machines with printing rollers because one blanket printing cylinder must be fixed for receiving the paper sheet.
Finally, the German Pat. No. 419,149 discloses a drive for a rotary offset printing machine with rollers in which by means of one linkage, the two blanket cylinders, which serve as printing cylinders, are moved into contact with the platen cylinders, and away from the same. The distance of displacement is so small that it is not sufficient for an acceptable separation of blanket printing cylinders on both sides of the web.